curl: curl: Information disclosure due to incorrect TLS connection reuse

A flaw was found in curl. A remote attacker could exploit this by initiating an unencrypted connection via IMAP, SMTP, or POP3 and then making a subsequent request to the same host that requires Transport Layer Security TLS. Due to incorrect connection reuse, the subsequent request would bypass t...

curl: libcurl 8.20.0 incomplete fix for CVE-2026-7168: changing only CURLOPT_PROXYPORT leaks stale Proxy Digest auth to a different proxy

Summary: I found an incomplete-fix variant of CVE-2026-7168 in curl 8.20.0. The 8.20.0 fix clears state.proxydigest / state.authproxy when CURLOPTPROXY changes, but not when only CURLOPTPROXYPORT changes. On the same easy handle, request 1 through proxyA CURLOPTPROXYPORT=18197 learns Proxy Digest...

Curl 7.14.1 < 8.20.0 Proxy Credential Disclosure

The version of curl installed on the remote host is 7.14.1 prior to 8.20.0. It is, therefore, affected by a proxy credential disclosure vulnerability: - curl might erroneously pass on credentials for a first proxy to a second proxy. This flaw occurs when different proxies are configured for...

Curl 7.10.6 < 8.20.0 Wrong Reuse of HTTP Negotiate Connection

The version of curl installed on the remote host is 7.10.6 prior to 8.20.0. It is, therefore, affected by an authentication bypass vulnerability: - libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS request after a Negotiate-authenticated one,...

Curl 8.17.0 < 8.20.0 OCSP Stapling Bypass

The version of curl installed on the remote host is 8.17.0 prior to 8.20.0. It is, therefore, affected by an OCSP stapling bypass vulnerability: - When curl is told to use the Certificate Status Request TLS extension, often referred to as OCSP stapling, to verify that the server certificate is...

Curl 7.40.0 < 8.20.0 Wrong SMB Connection Reuse

The version of curl installed on the remote host is 7.40.0 prior to 8.20.0. It is, therefore, affected by a wrong SMB connection reuse vulnerability: - libcurl might in some circumstances reuse the wrong connection for SMBS transfers. The code erroneously did not consider the share name as a...

CVE-2026-6253

A flaw was found in curl. When curl is configured to use distinct proxies for different URL schemes, a redirect from a URL using an authenticated proxy to one using an unauthenticated proxy can inadvertently expose the initial proxy's credentials. This improper credential management CWE-522 may...

CVE-2026-4873

A flaw was found in curl. A remote attacker could exploit this by initiating an unencrypted connection via IMAP, SMTP, or POP3 and then making a subsequent request to the same host that requires Transport Layer Security TLS. Due to incorrect connection reuse, the subsequent request would bypass t...

Important Photon OS Security Update - PHSA-2026-5.0-0838

Updates of 'curl' packages of Photon OS have been released...

CLSA-2026-1777463593 curl: Fix of CVE-2023-27533

CVE-2023-27533: telnet: only accept option arguments in ascii...

CLSA-2026-1777463367 curl: Fix of CVE-2023-27533

CVE-2023-27533: telnet: only accept option arguments in ascii...

CVE-2026-6253

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. whil...

UBUNTU-CVE-2026-6253

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. whil...

CVE-2026-5773

libcurl might in some circumstances reuse the wrong connection for SMBS transfers. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the...

Malicious code in apple-coredata-internal-service (npm)

Malicious npm package published by threat actor "raya4321" as part of a coordinated typosquatting campaign impersonating Apple internal infrastructure services authentication, PKI, telemetry, CloudKit, and cloud infrastructure. All packages in this campaign execute credential-theft payloads durin...

CURL-CVE-2026-5545 wrong reuse of HTTP Negotiate connection

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid...

Malicious code in apple-cloud-infrastructure-monitor (npm)

Malicious npm package published by threat actor "raya4321" as part of a coordinated typosquatting campaign impersonating Apple internal infrastructure services authentication, PKI, telemetry, CloudKit, and cloud infrastructure. All packages in this campaign execute credential-theft payloads durin...

proxy credentials leak over redirect-to proxy

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. whil...

wrong reuse of HTTP Negotiate connection

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid...

CURL-CVE-2026-6253 proxy credentials leak over redirect-to proxy

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. whil...